A Unique Object (UNO) is a physical object with unique characteristics that can be measured externally. The usually analogue measurement can be converted into a digital representation - a fingerprint - which uniquely identifies the object. For practical applications it is necessary that measurements can be performed without the need of specialist equipment or complex measurement setup. Furthermore, a UNO should be able to defeat simulation attacks; an attacker may replace the UNO with a device or system that produces the expected measurement. Recently a novel type of UNOs based on Quantum Dots (QDs) and exhibiting unique photo-luminescence properties has been proposed. The uniqueness of these UNOs is based on quantum effects that can be interrogated using a light source and a camera. The so called Quantum Confinement UNO (QCUNO) responds uniquely to different light excitation levels which is exploited for simulation attack protection, as opposed to focusing on features too small to reproduce and therefore difficult to measure. In this paper we describe methods for extraction of fingerprints from the QCUNO. We evaluate our proposed methods using 46 UNOs in a controlled setup. Focus of the evaluation are entropy, error resilience and the ability to detect simulation attacks.
A Unique Object (UNO) is a physical object with unique characteristics that can be measured externally. The usually analogue measurement can be converted into a digital representation - a fingerprint - which uniquely identifies the object. For practical applications it is necessary that measurements can be performed without the need of specialist equipment or complex measurement setup. Furthermore, a UNO should be able to defeat simulation attacks; an attacker may replace the UNO with a device or system that produces the expected measurement. Recently a novel type of UNOs based on Quantum Dots (QDs) and exhibiting unique photo-luminescence properties has been proposed. The uniqueness of these UNOs is based on quantum effects that can be interrogated using a light source and a camera. The so called Quantum Confinement UNO (QCUNO) responds uniquely to different light excitation levels which is exploited for simulation attack protection, as opposed to focusing on features too small to reproduce and therefore difficult to measure. In this paper we describe methods for extraction of fingerprints from the QCUNO. We evaluate our proposed methods using 46 UNOs in a controlled setup. Focus of the evaluation are entropy, error resilience and the ability to detect simulation attacks.
Ensuring secure authentication is a critical challenge in modern security applications. This study presents a novel approach utilizing the photoluminescence (PL) characteristics of non-toxic quantum dots (QDs) to generate unique optical fingerprints. PL measurements capture emission properties, which are processed through computational algorithms to extract distinct security identifiers. The results demonstrate that this method offers highly distinctive and reproducible optical signatures for authentication and anti-counterfeiting applications. By integrating experimental and computational techniques, this approach enhances precision and security. Future work will focus on optimizing stability and scalability for real-world deployment in secure authentication systems.
Modern technology unintentionally provides resources that enable the trust of everyday interactions to be undermined. Some authentication schemes address this issue using devices that give a unique output in response to a challenge. These signatures are generated by hard-to-predict physical responses derived from structural characteristics, which lend themselves to two different architectures, known as unique objects (UNOs) and physically unclonable functions (PUFs). The classical design of UNOs and PUFs limits their size and, in some cases, their security. Here we show that quantum confinement lends itself to the provision of unique identities at the nanoscale, by using fluctuations in tunnelling measurements through quantum wells in resonant tunnelling diodes (RTDs). This provides an uncomplicated measurement of identity without conventional resource limitations whilst providing robust security. The confined energy levels are highly sensitive to the specific nanostructure within each RTD, resulting in a distinct tunnelling spectrum for every device, as they contain a unique and unpredictable structure that is presently impossible to clone. This new class of authentication device operates with minimal resources in simple electronic structures above room temperature.
Modern technology unintentionally provides resources that enable the trust of everyday interactions to be undermined. Some authentication schemes address this issue using devices that give a unique output in response to a challenge. These signatures are generated by hard-to-predict physical responses derived from structural characteristics, which lend themselves to two different architectures, known as unique objects (UNOs) and physically unclonable functions (PUFs). The classical design of UNOs and PUFs limits their size and, in some cases, their security. Here we show that quantum confinement lends itself to the provision of unique identities at the nanoscale, by using fluctuations in tunnelling measurements through quantum wells in resonant tunnelling diodes (RTDs). This provides an uncomplicated measurement of identity without conventional resource limitations whilst providing robust security. The confined energy levels are highly sensitive to the specific nanostructure within each RTD, resulting in a distinct tunnelling spectrum for every device, as they contain a unique and unpredictable structure that is presently impossible to clone. This new class of authentication device operates with minimal resources in simple electronic structures above room temperature.
Unique identification of optical devices is important for anti-counterfeiting. Physical unclonable functions (PUFs), which use random physical characteristics for authentication, are advantageous over existing optical solutions, such as holograms, due to the inherent asymmetry in their fabrication and reproduction complexity. However, whilst unique, PUFs are potentially vulnerable to replication and simulation. Here we introduce an additional benefit of a small modification to an established model of nanoparticle PUFs by using a second measurement parameter to verify their authenticity. A randomly deposited array of quantum dots is encapsulated in a transparent polymer, forming a tag. Photoluminescence is measured as a function of excitation power to assess uniqueness as well as the intrinsic nonlinear response of the quantum material. This captures a fingerprint, which is non-trivial to clone or simulate. To demonstrate this concept practically, we show that these tags can be read using an unmodified smartphone, with its built-in flash for excitation. This development over constellation-style optical PUFs paves the way for more secure, facile authentication of devices without requiring complex fabrication or characterisation techniques.
The goal of optical target detection is to identify the presence or absence of a target object by using light or photons as the transmitter. This technique offers significant advantages, such as high resolution and precise directionality, and plays a key role in applications like LiDAR. One of the critical performance metrics in optical target detection is noise resilience─specifically, the system’s ability to distinguish reflected signals from crosstalk or jamming sources with similar optical properties. Traditionally, this challenge has been addressed through classical information processing or standard optical filtering methods. However, a new approach to improving noise resilience has recently captured the attention of numerous researchers: harnessing the unique properties of quantum light sources. These sources offer performance enhancements that are challenging or even impossible to achieve with conventional coherent optical sources. In this perspective, we examine the performance and limitations of this emerging method, including challenges related to receiver complexity and power scaling. We also explore potential strategies to overcome these limitations, highlighting the practical advantages these approaches could offer.
Quantum dots (QDs) have garnered significant attention for their unique size-dependent optical and electronic properties, enabling their widespread use in applications ranging from high-efficiency photovoltaics and light-emitting diodes to biomedical imaging and quantum computing. Their tunable emission, high photo-stability, and ease of surface modification make them ideal candidates for precision nanotechnology applications. In this work, we explore a novel and rapidly emerging application of QDs in hardware security through the development of Quantum Dot-based Physical Unclonable Functions (QD-PUFs). Unlike conventional security paradigms, QD-PUFs leverage the intrinsic physical randomness of QD-based nanostructures to generate challenge-response pairs with superior uniqueness, reliability, and robustness. We review the integration of QDs into PUFs, beginning with their material properties and extending to entropy sources arising from synthesis and fabrication, surface and encapsulation effects. A comparative analysis of different readout mechanisms and related applications underscores the unique encoding capacity and security potential of QD-based systems. By demonstrating their feasibility for scalable, high-security applications, this study underscores the transformative impact of QDs in next-generation authentication and anti-counterfeiting technologies.